Device for invisibly fastening panels to walls

ABSTRACT

A device for invisibly fastening panels, especially natural stone heating panels, to walls with the help of a holding element, engaging a blind recess of the panel, wherein the blind recess essentially is a T-shaped groove with a threading opening, which is engaged by the cross sectionally corresponding head of the holding device.

[0001] The invention relates to a device for invisibly fastening panels, especially heating panels of natural stone, to walls with the help of a holding element, which engages a blind recess in the panel.

[0002] Aside from the visible fastening by metal hooks, which are suspended from loops screwed to the natural stone panel, invisible means of fastening using straddling dowels of brass or undercut dowels, which are mounted in the back side of heating panels, have also already been proposed. A blind hole with a diameter of, for example, 8 mm and a depth of 14 mm is drilled with a diamond drill between the cable grooves into the back side of the heating panel, which usually is about 30 mm thick, and an M6 brass dowel is inserted. The borehole is dimensionally accurate to less than 0.2 mm in order to prevent turning of the dowel as the screw is being screwed in up to the start of the expansion process. However, contrary a twist drill for metal and wood, the diamond drill for working stone is subject to wear at the shaft diameter, so that the borehole increasingly becomes smaller.

[0003] Admittedly, in the case of the so-called undercut dowels, the problem described above is eliminated; however, it is paid for dearly by the very high purchase price of a special drilling device. Moreover, for both types of fastening, only permissible temperature ranges are in effect, which lie outside of the heating range, that is, far below 100° C., so that their use for natural stone heating panels practically does not come into consideration. Natural dimensional changes due to relative high temperature changes of the heating panel make the durability of the dowels in natural stone heating panels uncertain especially when a naturally produced crack (porous spot) is present, which is hardly visible to the eye.

[0004] It is therefore an object of the invention to configure a fastening device of the type named above, which is easily manufactured and installed, so that panels can be held securely and invisibly at walls without problems, even when the temperature differences are high.

[0005] Pursuant to the invention, this objective is accomplished owing to the fact that the blind recess essentially is a T-shaped groove with an expanded threading opening, which is engaged by the head of a holding element, the head having an appropriate cross section.

[0006] The holding element, which may be a binding stone or a sliding block, is inserted with its expanded head through the threading opening and then shifted along the groove up to the other end of the latter.

[0007] Preferably, the axis of the T-shaped groove should be disposed vertically and the threading opening for the holding element should be disposed at the lower end, so that the holding element is prevented from being unhooked by the weight of the panel. Especially if the groove, as can be provided for in a further development in the invention, is filled with a curing filling material, such as an epoxy resin, which is introduced after the holding element, protruding over the rear of the panel, is introduced, the orientation of the groove and the arrangement of the threading opening, can also be accomplished in a different manner.

[0008] A profiling cutter can be used to machine the inventive T-shaped groove. Aside from the possibility of forming the threading opening by means of a previously introduced blind borehole, through which a profiling cutter for introducing the T-shaped groove can be brought into the working condition, production in one step is also possible in that namely the groove is a curved groove, one end of which discharges in the rear side of the panel and is machined with the profiling cutter in one process. Filling the groove with a filling agent, especially with an epoxy resin, which remains elastic and which does not exert any splitting effects on the stone even if there are temperature changes, not only has the advantage of fixing the holding element independently of the orientation of the axis of the T-shaped groove, but also prevents penetration of water and, with that, corrosion of the holding element as well as freezing of the water in the groove, which can occur even in natural stone heating panels, once the heating panel is switched off for a prolonged period.

[0009] The holding element can be connected with the wall in different ways. For example, a U-shaped suspension hook can be used, the leg of which, in contact with the wall, can be screwed on or otherwise be fastened and to the other leg of which, lying in front of the fastened leg, the holding element can be hooked or also screwed or otherwise fastened.

[0010] Further advantages, distinguishing features and details of the invention arise out of the following description of an example and from the drawing, in which

[0011]FIG. 1 shows a section through a panel with a horizontal T-shaped groove, invisibly mounted in front of a wall,

[0012]FIG. 2 shows a section parallel to the axis of the T-shaped groove for illustrating the suspension of the binding stone used in FIG. 1,

[0013]FIG. 3 shows a plan view of the rear side of the panel before the binding stone is introduced,

[0014]FIG. 4 shows a plan view of the covering disk of the T-shaped groove,

[0015]FIG. 5 shows a side view of the covering disk of FIG. 4,

[0016]FIG. 6 shows a section, corresponding to that of FIG. 2, through a panel while a sliding block is being suspended,

[0017]FIG. 7 shows a section perpendicular to the sectional plane of FIG. 6

[0018]FIG. 8 shows a section through a panel parallel to the axis of the groove to illustrate the forming of the T-shaped groove by means of a profiling cutter and

[0019]FIG. 9 shows a section, corresponding to that of FIG. 8, through a panel for a different type of construction of the threading opening for the profiling cutter.

[0020] In FIG. 1, a panel 1 can be recognized, especially a natural stone heating panel, in which meander-shaped heating coils are inserted, which are not shown in the drawing. With the help of a U-shaped fastening hook 2 and a wall dowel 3, the panel is fastened invisibly to a wall 4. The leg 5 of the fastening hook, in contact with the wall, is fastened with the help of the wall dowel to the wall. On the other hand, the second leg 6 serves to hold an engaging holding element 7 directly in a blind recess of the panel 1. In the case of FIG. 1, this holding element 7 comprises a binding stone 8, the expanded head 9 of which corresponds in no dimensions essentially to the dimensions to the T-shaped groove 10. In the case of the examples of FIGS. 1 to 8, this T-shaped groove 10, which is produced in panel 1 with the help of a profiling cutter, is formed a curved groove, which ends at one end in the rear side 11 of the panel 1, so that it can be machined in one step, as can be seen in FIG. 9, with the help of a profiling cutter 13, which can be swiveled about a point of rotation 12 and is populated with diamonds in the front region 14. At the same time, a threading opening 15, through which either a binding stone 8 or, corresponding to FIGS. 7 and 8, a sliding block 8′ can be suspended with a hook part 16 for connection to the fastening hook 2, is formed in the rear side 11 of the panel 1.

[0021] Instead of machining an arc-shaped, T-shaped groove, this back-cut groove 10′ can also extend parallel to the rear 11 of the panel 1, as shown in FIG. 10. In this case, before the groove 10′ is machined with the help of the profiling cutter 13, as shown in FIG. 9, a threading opening 15, preferably in the form of a blind borehole, must be produced in the panel 1. The profiling cutter is inserted through this threading opening 15′ and then moved to the right in FIG. 10, so that the back-cut T-shaped groove 10′ is formed.

[0022] After the holding element, that is, either the binding stone 8 or the sliding block 8′, are introduced, in order to be able to fill the groove 10, 10′ particularly easily with a filling agent, for example, by injecting epoxy resin, a covering disk 20 (FIGS. 4 and 5) is provided in the examples shown. On the one hand, this covering disk 20 has a recess 17′ for the shaft of the binding stone or the holding part 16 of the sliding block and is fastened, for example with screws to the rear side with the help of these holding elements. On the other, it has an injection opening 18, through which the filling agent can be introduced. This injection opening 18 can be formed by a U-shaped stamping of the covering disk 20, so that, after the injection, the bracket 19 formed can be pressed backed into the plane of the covering plate 10, and, with that, closes off the groove, so that the filling agent can not run out before it has cured.

[0023] With respect to the orientation of the axis of the T-shaped groove, the respective conditions must be taken into consideration, that is, for example, the suspension orientation, which depends on the grain of the panel 1 and the direction, in which the heating coils are brought into the rear of panel 1. Of course, if there is only a small distance between the heating coils, the groove can only be parallel to the latter. This also determines whether the groove, during the suspension, extends horizontally or vertically. If the groove is injected, this orientation plays no role whatsoever, if not, it should as far as possible be perpendicular with a threading opening disposed at the underside. 

1. A device for invisibly fastening panels, especially natural stone heating panels, to walls with the help of a holding element, engaging a blind recess of the panel, wherein the blind recess essentially is a T-shaped groove (10, 10′) with a threading opening (15, 15′), which is engaged by the cross sectionally corresponding head of the holding device (7).
 2. The fastening device of claim 1, wherein the holding device (7) comprises a binding stone (8).
 3. The fastening device of claim 1, wherein the holding device (7) comprises a sliding block (8′).
 4. The fastening device of claims 1 to 3, wherein the axis of the T-shaped groove (10, 10′) is disposed vertically and the threading opening (15, 15′) for the holding elements (7) is disposed at the lower end.
 5. The fastening device of one of the claims 1 to 4, wherein the threading opening (15′) is a blind borehole, through which a profiling cutter (13) can be brought into the working position for machining the T-shaped groove.
 6. The fastening device of one of the claims 1 to 4, wherein the T-shaped groove (10) is a curved groove, which ends at one end on the rear side (11) of the panel (1) and is machined by means of a profiler cutter (13).
 7. The fastening device of one of the claims 1 to 6, wherein the T-shaped groove (10, 10′) is filled with a curing filling agent after the holding part (16), protruding over the rear (11) of the panel (1), is introduced.
 8. The fastening device of claim 7, wherein the filling agent is an epoxy resin.
 9. The fastening device of one of the claims 1 to 8, with a covering plate (20), which covers the T-shaped groove (10, 10′) with its threading opening (15, 15′), preferably is fastened to the holding element (16) and optionally is provided with an opening (18) for injecting the filling agent. 